1. Field of the Invention
This invention relates to fuel and lubricant additives. More particularly, it relates to Mannich base products made from a high molecular weight alkyl-substituted hydroxyaromatic compound an aldehyde and a polyoxyethylenepolyamine.
2. Discussion of the Prior Art
A great deal of effort is being directed to providing a lubricant which will permit present-day automotive engines to be operated at a high level of efficiency over long periods of time. A difficulty arises because lubricating oils tend to deteriorate under the conditions of use, with attendant formation of sludge, lacquer and resinous materials which adhere to the engine parts, thereby lowering the operating efficiency of the engine. To counteract the formation of these deposits, certain chemical additives have been found which, when added to lubricating oils, have the ability to keep the deposit-forming materials suspended in the oil, so that the engine is kept clean and in efficient operating condition for extended periods of time. These added agents are known in the art as detergents or dispersants.
Metallo-organic compounds are particularly useful as additives in this respect. However, the troublesome deposits which form on the skirt of the piston and on the walls of the combustion chamber, as well as on valves and spark plugs are also partially attributable to these metal containing additives employed in the lubricant. Whenever oil is burned in the engine, as occurs with the oil film present on the cylinder wall during the combustion stroke, many metal containing additives present in the oil may form an ash which is partially deposited on the various surfaces of the combustion chamber and on those of the spark plugs and valves.
Several known non-metallic detergents have previously been used in lubricating compounds. However, they have not proved to be entirely satisfactory. Additives which are particularly effective are based upon condensation products of an hydroxyaromatic, an aldehyde and an amine, the so-called Mannich reaction. These additives are multi-functional improvers especially adapted for mineral oils and as pour depressants therein. These compounds have also been recognized as exhibiting detergent properties. A preference has existed for the use of hydroxyaromatics which are unsubstituted, particularly phenol and alpha and beta naphthols. Hydroxyaromatic compounds which are substituted by a short chain alkyl group or by a relatively high molecular weight straight chain chlorinated aliphatic hydrocarbon are also suitable such as the wax phenols, referred to by E. A. Oberright, U.S. Pat. No. 2,459,144.
U.S. Pat. No. 3,734,965 discloses the use of short-chain phenols in making a phenolic resin. The reaction to produce such resin involves phenol per se or a short chain-substituted hydroxyaromatic compound, a polyoxyethylenepolyamine and an aldehyde. There is, however, no disclosure of the compounds having long chain-substituted phenol or of their use as fuel and lubricant additives.